An oscilloscope is an instrument for graphically displaying measured electrical parameters, such as voltage. Typically, an oscilloscope's graphical display includes a two-dimensional plot of the electrical parameter versus time.
Originally, oscilloscopes were analog devices, which displayed their graphics on a cathode ray tube (CRT). Newer types of oscilloscopes are digital. For example, a digital storage oscilloscope (DSO) can convert analog signals to digital form, store those signals, and process the signals for display, typically on a liquid crystal display (LCD) device.
DSOs having two channels are known. One type of DSO is capable of receiving two input analog signals (one per channel), digitizing those signals, relating those signals to a single internally-detected trigger event, and displaying a resulting graphical image.
An asynchronous trigger signal may be generated in response to a trigger event in one two-channel DSO. It is known to provide that asynchronous trigger signal to another two-channel DSO in an attempt to relate more than two signals to that same trigger event.